Friday, October 26, 2012

Deflationism and the role of the truth predicate

To: Chris M.
From: Geoffrey Klempner
Subject: Deflationism and the role of the truth predicate
Date: 22nd October 2008 11:44


Dear Christian,

Thank you for your email of 12 October, with your University of London BA Logic Essay in response to the question, 'Deflationists claim that the predicate "true" does not stand for any property. What do they claim is the role of this predicate, and can this claim be justified?'

This is a good essay. However, I have to be frank, and say that I am not sure what this question is asking. There are two possibilities: (a) What according to deflationists is the role for the truth predicate and how good are their arguments for saying that it has that role? (b) What according to deflationists is the role for the truth predicate? Is that the only role for truth, or are there other roles which they have not considered?

You have answered version (b). You criticize to some extent the explanation of truth as equivalent in representational power to generalizations about propositions, but the main focus of your attack is on the idea that this role exhausts the significance of the truth predicate. You need to be aware that there is a lot more to say about the equivalence claim: for example, that the very idea of 'quantifying over propositions' is nonsensical (on both 'substitutional' and 'objectival' interpretations).

However, I would tend to defend the deflationists on this point, on the grounds that the representational 'power' of the truth predicate makes it possible to say things which we could not otherwise do given that sentences and the time we have to assert them are both finite. In other words, the idea of 'representational power' should not be construed in terms of the old (and questionable) concept of analyticity, where two expressions occur on opposite sides of an equivalence sign.

I share your intuition that leaving aside the resolution of question (a) there is 'something more' to truth. The problem, however, is to state this coherently.

Let's start at the beginning. If I wanted to invent an operator N, which I shall call the 'null operator' which when applied to any proposition P gives a result with the same truth value as P, then the assertion N(P) would have exactly the same effect as 'It is true that P'. I am not talking about truth. I am just asserting P. However, if you hear the assertion, 'N(P)' then you at least know that P is intended as an assertion. (Compare 'I do not command that P' and 'I command that not-P'.)

How different is this from your, 'The statement that "Caesar was murdered" is true'? We need to be exact. In the sentence I have just quoted, the term 'that' is redundant because what follows is a quotation. Removing the 'that', we have a statement about words (as you point out) rather than just a statement about Caesar. So it is quite plausible here to say that when we invoke the predicate 'true', we are saying more than we would be saying if we did not invoke it. 'Caesar was murdered' is about the world. 'The statement, 'Caesar was murdered' is true,' is about words and the world.

But how important is that observation? To assert a truth, you need language and words. That's all this seems to be saying.

However, you want to go further and argue that there is an additional issue: truth is what you can rely and act upon. This is reminiscent of Michael Dummett's claim (in his seminal article 'Truth' reprinted in 'Truth and Other Enigmas') that the essential thing about the concept of truth, what makes truth something that is not merely redundant, is that 'truth is what we aim at in making a statement.'

However, I don't think you have succeeded in making this point convincingly. Suppose you ask me, 'Was Caesar murdered?' and I reply, laconically, 'Caesar was murdered.' My reply doesn't satisfy you. 'But *was* he murdered? was he *really* murdered?' 'Yes! Caesar was *really* murdered!' I reply. You can see here that all we have added in the second exchange is increased emphasis. This is in fact a claim made by deflationists; that in one of its everyday roles 'it is true that' is merely a device for increasing emphasis.

What this misses is a metaphysical question, or rather a question at the intersection of metaphysics and the philosophy of language, namely, 'What is it to state something?' or 'What is the point of assertion?' In answering that question, the philosopher needs to use the concept of truth, precisely because it is the philosopher who raises questions which in ordinary language we do not consider, namely, 'What is this mysterious relationship between words and the world which makes it possible to say things?'

It is that this point that a philosopher like Dummett will come in and claim that 'truth' does not have the centrality that philosophers have claimed for it, on the grounds that it invites false metaphysical claims about the nature of linguistic meaning (I am talking now about Dummett's arguments for an 'anti-realist theory of meaning' which attempts to articulate Wittgenstein's claim that 'meaning is use'). Yet here too, the philosopher needs to talk about truth in order to express their view dialectically, 'Truth isn't what you think it is,' or 'An assertion is a move in the language game, not an arrow aimed at a potentially unreachable target.'

This is just one possible angle, which illustrates the indispensability of the concept of truth within philosophical discourse and which (in a way) accepts that in ordinary, non-philosophical discourse by contrast, truth is redundant, or at best a mere device for abbreviation or emphasis.

All the best,

Geoffrey